Ashar-
Hello,
I have made some profiling loading my mediawiki main page ( http://www.twenkill.net/wiki/ ) wich use phptal monobook skin and is set to use the french language. For profilling I used "Advanced php profiler".
Let's not forget intermittent slow queries, we still have a few of them. Watchlists are still quite slow - I haven't looked into how the wl_cache works, but it doesn't seem to use cached data for generating new watchlists (i.e. only lookup changes that aren't in the cache). Ancientpages bogged down the server recently, it doesn't seem to be using the index properly; we may want to add it to the query cache for the time being. Special:Contributions gets slow when people start digging with large offsets. Special:Undelete appears to have no paging, which makes it slow when the archive is large.
Regards,
Erik